The present invention pertains to a universal connection system for connecting pipes joined together, pipe ends provided with a straight cut and/or with a miter cut for straight, crossed, T-shaped as well as acute-angled and obtuse-angled pipe connections as well as for connecting pipes with elbow, pipe bends, sections, hollow sections and plates, as shaping elements, such as handrails, exhibition and display elements, for pipe systems for ducting cables as well as for all types of gaseous and liquid media.
Systems for connecting pipes have been known, in which the locations of the joints are connected to one another by connecting sleeves or union nuts. Standardized connection elements such as T-pieces, elbows and pipe bends, which must be provided with internal threads at the end and into which pipe ends provided with external threads are screwed, are used to connect pipes in angular areas of rooms. These systems have the drawback that the pipe connection is visible and unattractive from the outside and the manufacture and mounting is complicated and expensive. Welded pipe connections are known as well, and even though they guarantee relatively flat transitions at the connection points, they must be destroyed if repair becomes necessary or if the course of the pipeline must be changed, and deformation and above all destruction of the surface protection, which cannot be repaired, usually occur.
A pipe connection system has been known from DE 297 09 986 U1, which provides for the connection of a pipe section especially of stair handrails and the like with a spherical corner part, which has at least one threaded hole with a hole axis extending through the center of the sphere, where the connection pin has, on the sphere side, a recess with a support surface adapted in some areas to the spherical surface and a hole opening in the area of the recess for a fastening screw which can be screwed into the threaded hole and whose screw head is supported on a curved abutment surface of the connection pin, whose radius originates from the center of the sphere with the connection pin brought into contact with the sphere, wherein a special abutment is designed, which is introduced into the interior of a pipe and is screwed by the front-side opening of the pipe to the spherical corner part. The drawback of this system is that the abutment requires a specially shaped pipe end which is used as an abutment within the pipe. The manufacture of such a pipe connection is complicated and expensive.
DE 195 25 334 A1 discloses the design of a kit comprising various round rods for building a round rod system bent at right angles. To make do with the smallest possible number of round rods of a compact design, it is proposed that the round rod be provided at least at one end of the rod with a hemispherical closure, which has the same radius as the round rod in order to recess circular cylindrical recesses in this closure. The cylinder radius of the recess is equal to the radius of the circular section of the round rod and intersects the axis of the cylinder in the axis of the rod. A sickle-shaped segment is thus formed in the inner angle area between the intersecting axes of the rod and the cylinder. This solution is an elegant connection for round sections, which can be assembled with one another by means of threaded bolts. However, they are not suitable for pipes due to their designed central screw connection and their manufacture is complicated and expensive.
DE 298 11 026 U1 discloses a connection system for pipes, which is characterized by a spreadable sleeve, which is arranged in at least one pipe end, where the said pipes are connected to one another by conical washers arranged on both sides and a spacing washer by means of a centrally arranged setscrew and in which system the spreadable sleeve is axially clamped in the pipe by a mounting pin that can be screwed radially into the spacing washer. The spacing washer with the opening for the mounting pin can be seen between two pipe joints in the assembled state. Additional spacers and split fittings with different angles are needed for a T-shaped pipe connection or a connection with pipe bends. This pipe connection is based on a central connection of the clamped parts, which closes the pipe system at the connection points. These pipe connections are not suitable for pipe systems in which gaseous or liquid media are to be carried or cables are to be ducted. In addition, each pipe connection is characterized by the spacing washer, which is visible from the outside and is arranged between pipe ends, which is optically disturbing and questionable in terms of safety engineering because the connection point is recognizable and accessible to anyone.
The basic object of the present invention is therefore to provide a universal connection system with invisible connection elements for pipes joined together with straight cut and/or with miter cut as well for pipe ends provided with a miter cut with radii made in one piece for straight, T-shaped, crossed as well as acute-angled and obtuse-angled pipe connections as well as for connection pipes to elbows, pipe bends, sections, hollow sections and plates, which is also suitable for pipe systems for ducting cables as well as for carrying all types of gaseous and liquid media.
According to the invention, the connection system comprises clamping systems and/or clamping systems coupled with straight and/or hinge-shaped connection elements with axially and radially movable tie-in points which can be provided and which are to be connected to one another in a great variety of manners by threaded bolts which can be arranged centrally. A simple design of the individual parts and their connection is provided. It makes possible an extremely inexpensive manufacture of the individual parts and simple assembly. The variable usability of the clamping systems alone as well as in conjunction with additional clamping systems and/or with various connection elements with axially and radially movable tie-in points arranged as needed guarantees, due to the arrangement of threaded bolts, a straight, T-shaped and crosswise as well as acute-angled and obtuse-angled connection of pipe sections with one another or of pipe sections with solid sections, elbows, pipe bends, plates and the like, which said connection can be assembled in a simple manner. The clamping systems and connection elements, which are designed as permeable, and pipe connections provided with sealing elements make possible the use of the universal connection system not only for shaping elements such as handrails and display elements, but also for pipe systems for ducting cables as well as for carrying gaseous and liquid media.
A special advantage of the universal connection system according to the present invention is that it can be locked from the open front sides of the pipes and completely disappears in the pipes, as a result of which a pipe connection point meeting any optical requirements and all safety engineering requirements concerning unauthorized tampering with such a connection are met.
The design of the clamping systems, in particular, makes possible the preassembly of the clamping system before use in the pipe, as a result of which the mounting of the pipe connections is simplified and thus it can be carried out at a low cost. Due to an axial three-screw tension distributed on the circular areas of the connection, the connection of the clamping system ensures an absolutely stable and adaptable radial tension in the pipe, which tension equalizes especially unevennesses in the inner pipe. The passage openings arranged in the clamping system and distributed over the circular areas form channels, which ensure the permeability for gaseous and liquid media or for ducting cables. The clamping systems can be used only as a straight connection element and, in a second embodiment of the ring washer with radially arranged through threaded hole, the clamping systems may also be used for a T-shaped and crossed connection only. The through hole arranged centrally in the parts of the clamping systems and provided with internal thread makes possible a simple screw connection by means of threaded bolts of various lengths with additional clamping systems or connection elements according to an embodiment as well as their ready radial locking with tightening screws arranged axially in the clamping systems or with nuts arranged on the end side on a central threaded bolt, by means of straining rings in the pipe.
The connection element according to an embodiment is also advantageous; due to its hollow section and the end-side and central as well as crosswise mounts for arranging tie-in points according to an embodiment, it makes it possible to prepare not only a straight, T-shaped or crossed pipe connection, but also and especially a pipe connection which can be regulated easily and individually in the pipe during mounting along the axis of the pipe and can be an acute-angled and obtuse-angled pipe connection whose slope angle can be adjusted as needed in the range of 180xc2x0 on both sides of the pipe axis according to another embodiment, which can likewise be locked via the open front sides of the pipe sections. In addition, other elements such as solid sections, plates or tumbuckles may also be arranged directly at the central tie-in point of this connection element according to an embodiment by means of threaded bolts made in one piece with or screwed into the elements.
The radially pivotable connection element according to an embodiment is particularly advantageous because it comprises two hinge legs which are connected to one another by a hinge pin and are provided at their free leg ends with mounts each for the arrangement of tie-in points and which can be connected to clamping systems by means of threaded bolts and make possible, besides straight pipe connections, especially pipe connections which can have bends in the range of  less than 45xc2x0 to 180xc2x0 on both sides in relation to the axes of the hinge legs. One embodiment provides a compact and short form of the hinge legs and the second embodiment provides an extended form of the hinge legs. Even though the second embodiment somewhat limits the minimum angular position of the hinge legs in relation to one another, it also guarantees stable locking in an angular pipe connection which is exposed to especially high loads.
The tie-in points according to an embodiment, which are arranged on the connection elements, should be pointed out as well; they comprise a hinge pin designed as a turned part with a central threaded through hole arranged at right angles to the axis of the pin, which can be inserted into two oppositely arranged mounting points of the connection elements such that it is axially and radially movable. Due to the mobility of the tie-in points, a threaded bolt screwed into the hinge pin can also perform a radial movement axially and radially. This possibility of mobile arrangement supports an adaptable radial centering and spreading of the clamping systems preassembled with connection elements in the pipe sections even if the inner pipe jackets have certain unevennesses.
Furthermore, the variability of the universal connection system according to the present invention is characterized by its ability to be combined with elements according to an embodiemt, e.g., also with turnbuckles, which is made possible by a left-handed thread which can be provided in the clamping systems and stresses the versatile applicability of the connection system.
An advantageous embodiment of the pipe ends with a chamfer extending toward the center of the pipe according to an embodiment guarantees such an accurate connection point in the case of pipe connections for shaping elements or for cable ducts that it is not disturbing at all if the pipe system is formed by many short pipe sections. In addition, this has the advantage that the pipe sections can be subjected to surface treatment without problems and shaping requirements, even gold-plating, can be easily complied with.
Another advantageous embodiment of the pipe ends with a two-step chamfer extending toward the center of the pipe according to an embodiment is especially suitable for pipe systems which are intended for carrying liquid or gaseous media. Sealing elements are arranged in the second step of the chamfers within the pipes, and the sealing elements according to an embodiment may have different shapes corresponding to different requirements.
The closure of pipe system ends according to an embodiment by means of a machine screw with a plain washer placed under it and with a sealing element inserted on the clamping system instead of the last straining ring supports the flexibility of the universal connection system especially in the case of pipe systems carrying gaseous and liquid media.
The design of the universal connection system according to an embodiment is particularly advantageous. The design of the clamping systems used here, which are screwed to an inner connecting sleeve and are equipped with axially and radially acting seals, guarantees, on the one hand, a flat, center-free axial pipe passage at the pipe transitions, which passes slidingly over into the internal pipe diameter on both sides of the connection system, and, on the other hand, an axially and radially acting liquid- and gas-tight and pressure-sealed pipe connection. Not only does this embodiment of the universal connection system make possible an invisible, optically attractive pipe connection but it also ensures, especially in the case of use in the food industry, that liquid or fluid residues will not be left at the pipe connections and the associated risk of the growth of bacteria or the accumulation of media residues and the accompanying clogging of the pipes will be avoided. The sealing provided between the front surfaces of the clamping systems may be a ring seal or a sheet gasket, which may consist of various materials, e.g., copper, but is also heat resistant up to 900xc2x0 C. in the case of thin-walled pipes for heated media, and for foods, it consists of Gylon 3501 E, which is also heat resistant up to 230xc2x0 C. and it consists of vulcanized fiber for acids or alkalies. The use of materials for the seals according to the needs has no adverse effects on tightness, but it considerably broadens the scope of use of the connection system.
The clamping systems according to an embodiment are designed such that all parts which form unevennesses on the surface, such as straining rings, conical rings, sealing rings and ring nuts, are kept away from the inside of the pipe by mounting cylinders, which are flat on the inside. Moreover, the chamfer prepared on the inside of the collar of the mounting cylinder, guarantees the nearly continuous transition of the pipe connection to the internal pipe diameter of the pipe sections connected to one another. The chamfer segments, which are prepared axially on a front surface of the mounting cylinder, interrupt the external thread in these areas and guarantee the front-side locking and bracing of the clamping system are finally also hidden by the seal arranged between the front surfaces of the clamping systems within the inner connecting sleeve, which seal consists of a material adapted to the particular medium. In a second embodiment, the mounting cylinder is provided on one side, in the inner area of the collar, with a central threaded hole and with passage openings arranged radially around same, which also makes possible all types of non-straight pipe connections, besides the rather uncomplicated front-side bracing technique of the clamping systems with the locknut wrench.
The clamping systems according to an embodiment can be preassembled very easily without special prior know-how and locked in the pipe sections to be connected with a locknut wrench by screwing the ring nut against the collar of the mounting cylinder. The straining rings are now pressed radially against the inner walls of the pipe via the conical surface of the conical rings and the clamping systems are locked and braced. At the same time, the radial sealing of the clamping systems within the pipes at a pipe joint to be connected takes place during this operation, which is guaranteed by the sealing rings which are arranged on the mounting cylinder between the conical rings and which are pressed together axially flatly by the firm tightening of the ring nut against the collar of the mounting cylinder, and their remaining material surface at the outer ring undergoes such a structural change due to the pressing operation that they press the inner pipe jacket very tightly. At the same time, the axial liquid-, gas- and pressure-resistant sealing of the connection system is guaranteed by the screwing together of the clamping systems via the inner connecting sleeve and the seal, which is arranged between the front surfaces of the mounting cylinders within the inner connecting sleeve and whose material and shape are adapted to the particular medium.
The locknut wrench and its use according to embodiments comprises two ring socket wrenches which can be rotated around an axis and whose shape and size are adapted to the particular embodiment of the mounting cylinders and the ring nuts. It ensures a simple locking and tensioning of the clamping systems in the pipe ends, which are to be joined together in an abutting relationship and prevents tampering with the pipe connection by unauthorized persons.
Finally, the fact that all parts of the universal connection system are manufactured from stainless steel and the sealing elements are manufactured from acid-resistant material according to an embodiment guarantees that damage due to corrosion is ruled out and any type of surface treatment as well as connections with all materials and the carrying of gases and liquids, even those that are corrosive, e.g., acids and alkalies, or those that have to be compatible with foods, are possible in the pipe systems. Moreover, the exclusive use of sections and/or turned and milled parts as well as the use of standardized parts simplifies the manufacturing and mounting process and ensures an extremely inexpensive manufacture, mounting and maintenance of the universal connection system.